In the testing of engines and particularly internal combustion engines such as gasoline burning and diesel engines, it is often desirable to ascertain information concerning the consumption of engine lubricating oils. By ascertaining such information, much knowledge can be gained regarding the events occuring within the engine during the operation thereof. The functions which are in part determined by oil consumption include the efficiency of the piston rings, valve operation and overall engine efficiency. The previous system for maintaining the desired oil level in a test engine and measuring the rate of oil consumption circulated the oil between the engine and the tank of fresh oil and weighed the oil mechanically on a balance scale. At the beginning of a test, considerable time was required to stabilize the oil from an unsettled condition brought about by an elevation in temperature, dilution of the oil by fuel, and contamination before being able to obtain accurate oil consumption data.
Also, at the conclusion of a test, the used oil was often discarded after all critical measurements were made.